SRI CHAITANYA TECHNO SCHOOL
NAGARBHAVI
INVESTIGATORY PROJECT
ON
ESTIMATION OF AMOUNT OF ACETIC ACID
IN VINEGAR
SUBMITTED BY:
KARAN S
12th
SUBMITTED TO:
T SRINIVAS RAO
(CHEMISTRY LECTURER, SRI CHAITANYA TECHNO SCHOOL)
TABLES OF CONTENT
1. Acknowledgement
2. Abstract
3. Theory
4. Experiments
5. Materials required
6. Calculations
7. Procedure
8. Conclusion
9. Bibliography
ACKNOWLEDGEMENT
In the accomplishment of this project
successfully, many people have best owned
upon me their blessings and the heart
pledged support, this time I am utilizing to
thank all the people who have been
concerned with project. Primarily I would
thank god for being able to complete this
project with success. Then I would like to
thank my CHEMISTRY teacher T Srinivas
Rao Sir as well as Harish Sir, whose valuable
guidance has been the ones that helped me
patch this project and make it full proof
success their suggestions and his
instructions has served as the major
contributor towards the completion of the
project. Then would like to thank my parents
and friends who have helped me with their
valuable suggestions and guidance has been
helpful in various phases of the completion of
the project.
ABSTRACT
Measuring the Amount of Acetic Acid In
Vinegar by Titration with an Indicator
Solution. The goal of this project is to
determine the amount of Acetic Acid in
Different types of vinegar using titration with
a coloured pH indicator to Determine the
endpoint.
THEORY
Vinegar is a solution made from the fermentation
of ethanol (CH3CH2OH), which In turn was
previously fermented from sugar. The fermentation
of ethanol results
In the production of acetic acid (CH3COOH). There
are many different types of Vinegar, each starting
from a different original sugar source (e.g., rice,
wine, malt, Etc.). The amount of acetic acid in
vinegar can vary, typically between 4 to 6% for
Table vinegar, but up to three times higher (18%)
for pickling vinegar. In this project, We will
determine the amount of acid in different vinegars
using titration, a Common technique in chemistry.
Titration is a way to measure the unknown
Amount of a chemical in a solution (the titrant) by
adding a measured amount of a Chemical with a
known concentration (the titrating solution). The
titrating solution Reacts with the titrant, and the
endpoint of the reaction is monitored in some way.
The concentration of the titrant can now be
calculated from the amount of titrating
Solution added, and the ratio of two chemicals in
the chemical equation for the Reaction. To
measure the acidity of a vinegar solution, we can
add enough hydroxyl ions to balance out the
added hydrogen ions from the acid. The hydroxyl
ions will react with the hydrogen ions to produce
water. In order for a
Titration to work, we need three things:
1. A titration solution (contains hydroxyl ions with
a precisely Known concentration),
2. A method for delivering a precisely measured
volume of the Titrating solution
3. Means of indicating when the endpoint has been
reached. For the titrating solution, we'll use a
dilute solution of Sodium Hydroxide (NaOH).
Sodium Hydroxide is a strong base, which means
that it dissociates completely in Water. So for every
NaOH molecule that we add to the solution, we
can expect to Oroduce a hydroxyl ion. To dispense
an accurately measured volume of the titrating
Solution, we will use a burette. A burette is a long
tube with a valve at the bottom and graduated
markings on the outside to measure the volume
contained in the burette.
The burette is mounted on a ring stand, directly
above the titrant solution (as shown in the
picture), Solutions in the burette tend to creep up
the sides of the glass at the surface of the liquid.
This is due to the surface tension of water. The
surface of the liquid thus forms a curve, called a
meniscus. to measure the volume of the liquid in
the burette, always read from the bottom of the
meniscus.
In this experiment, We will use an indicator
solution called phenolphthalein. phenolphthalein
is colourless when the solution is acidic or neutral.
when the solution becomes slightly basic,
phenolphthalein turns pinkish, and then flight
purple as the solution becomes more basic. so
when the vinegar solution starts to turn pink, we
know that the titration is complete
MATERIALS REQUIRED
To do this experiment we will need the following
materials,
Apparatus and Materials:
Vinegar, three different types.
Distilled water
Small funnel -0.5% Phenolphthalein solution
in alcohol (pH indicator solution)
-0.1 M sodium hydroxide solution
125 mL Conical flask 25 or 50 mL burette
10 ml graduated cylinder
Ring stand Burette clamp
CALCULATIONS
Required amount of sodium hydroxide (NaOH) can
be calculated using the following formula
W= Molarity x Molar mass x Volume(cm)
1000
Molar mass of NaOH = 40 g/mol
0.5 x 40 x 500=1000
10 g
The acetic acid content of a vinegar may be
determined by titrating a vinegar sample with a
Solution of sodium hydroxide of known molar
concentration (molarity). CH3COOH + NaOH
CH3COONa+
H20 (Acid)+(Base) (Salt) + water
At the end point in the titration stoichiometry
between the both solution lies in a 1:1 ratio.
MCH3COOH VCH3C00H/MNaoH VNaoH =1/1
Strength of acid in vinegar can be determined by
the following formula:
Strength of acetic acid = MCH3COOH x 60
PROCEDURE
Performing the Titration
Pour 1.5 ml of vinegar in an Conical flask
Add distilled water to dissolve the vinegar so
that the volume of the solution becomes 20 ml.
Add 3 drops of 0.5% phenolphthalein
solution..
Use the burette clamp to attach the burette to
the ring stand. The opening at the Bottom of
the burette should be just above the height of
the conical flask we use for the solution of
vinegar and phenolphthalein solution.
Use a funnel to fill the burette with a 0.1 M
solution of sodium hydroxide..
Note the starting level of the sodium hydroxide
solution in the burette. Put the Vinegar
solution to be titrated under the burette. 7.
Slowly drip the solution of sodium hydroxide
into the vinegar solution. Swirl the flask gently
to mix the solution, while keeping the opening
underneath the burette.
At some point we will see a pink colour in the
vinegar solution when the sodium Hydroxide is
added, but the colour will quickly disappear as
the solution is mixed. When this happens,
slow the burette to drop-by-drop addition.
When the vinegar solution turns pink and
remains that colour even with mixing, The
titration is complete. Close the tap (or pinch
valve) of the burette.
Note the remaining level of the sodium
hydroxide solution in the burette. Remember
to read from the bottom of the meniscus.
Subtract the initial level from the remaining
level to figure out how much titrating solution
we have used.
For each vinegar that we test, repeat the
titration at least three times.
RESULT
Strength of acetic acid in household vinegar:
40.5 g/L
Strength of acetic acid in wine vinegar:
72 g/L
Strength of acetic acid in fruit vinegar :
48 g/L
CONCLUSION
Transference of measured vinegar into a
measuring flask should be done Very carefully.
Measuring must be performed carefully.
Look at the meniscus of solution at eye level to
avoid parallax.
Look at the lower meniscus in the light
coloured solution and upper
Meniscus in the dark coloured solution
because of visibility.
Do not forget to add distilled water to the
vinegar.
BIBLIOGRAPHY
NCERT Chemistry-XII
Sciencekids.com
http://www.sciencekids.co.nz/experiments/in
visibleink.html
http://www.si.umich.edu/spies/methodsink.h
tml
http://www.sciencedirect.com/science
https://www.stevespanglerscience.com/lab/ex
periments/secret-lemon-juice-messages/
https://www.youtube.com/watch?v=9G7vYtO
u4A&feature=emb
https://www.youtube.com/watch?v=KOWC7
ciwos
